1. Field of the Invention
The present invention relates to the detection of lymphedema using x-ray scans, e.g., with use of a dual-energy absoptiometry (DXA) system.
2. Background of the Art
For treatment of invasive breast cancer, surgeons generally remove some of the lymph nodes under a patient's arm during a lumpectomy or mastectomy. The reason for lymph node removal is twofold. Because the lymphatic system is a whole body system, lymph nodes may be intentionally removed in order to reduce the opportunity for spread of cancer cells throughout the body. In addition, lymph nodes may be unintentionally removed because they are interwoven with axilla breast tissue within the body; removal of breast tissue unavoidably results in removal of lymph nodes.
The removal of lymph nodes may cause a lymphatic obstruction which blocks the lymph vessels that drain fluid from tissues throughout the body and allow immune cells to travel where they are needed. A lymphatic obstruction may in turn cause lymphedema, i.e., swelling due to the blockage of the lymph passages. Lymphedema is a feared complication of cancer treatment and one that negatively impacts survivorship. Lymphedema is a chronic disease that usually requires lifelong management as it may result in complications such as chronic wounds and ulcers, skin breakdown and lymph-tissue types of cancers. Early detection of lymphedema may reduce the amount of swelling, discomfort and risk for a patient.
Whole body scanning is one approach to estimating body mass or assessing assorted body compositions, such as distribution of fat, lean mass, bone, and fat mass index. One problem with using a whole body scanning system to estimate body mass involves the delineation of body parts during the scan. In particular, when a patient lies in the supine position, there is a tendency for extra chest tissue, such as the patient's breasts, to fold over onto the arm. Similarly, if the patient's feet and legs are spaced too close together, there may be difficulties delineating the individual masses of the legs. Overlapping tissue during the scan can decrease the accuracy in body mass measurements for the individual body parts.